The present invention relates to a liquid separation device for the separation of liquids or liquid mist from a gas. It relates in particular to an oil or oil mist separator for the separation of oil and/or oil mist from blow-by gases of an internal combustion engine and to a water separator for the separation of water from the exhaust gases of a fuel cell stack. The present invention further relates to a valve cover for an internal combustion engine and an internal combustion engine provided with such a valve cover.
Liquid-gas separation devices as in the present invention are used for the separation of liquid or liquid mist from a gas. Such separators are for instance used for the separation of oil or oil mist from blow-by gases, which are also referred to as crankcase gases of internal combustion engines. A further possible area of use for liquid-gas-separators consists in the area of fuel cells, in particular such fuel cells, which operate with H2O-humidification and/or in which H2O is produced as a reaction product, meaning in particular PEM or alkali fuel cells. In such fuel cells, the supplied reaction gases are usually humidified prior to their inlet. On the other hand, pure water is produced on the cathode side of the fuel cell as a reaction product, so that here a considerable excess of water is given on the exhaust side in the exhausted gases. This water excess condenses immediately after having left the fuel cell. In order to separate this water from the exhaust gases, liquid separators are used, too.
A starting point for the present invention are liquid separators as they are for instance described in DE 10 2004 037 157 A1. These liquid separators belong to the class of tube separators, as they comprise a passage tube with an inlet and an outlet for the gas to be purified. It is in general possible that it comprises a separate outlet for the separated liquid, but such an outlet is not mandatory.
The liquid separators described in DE 10 2004 037 157 A1 may comprise two basic carriers. Each of these basic carriers comprises passage tubes, in which helical segments are arranged as additional liquid separator elements. The passage tubes of each basic carrier in the flow direction of the gas are arranged one behind the other. The helical elements in the basic carriers may be arranged with identical sense of rotation or with opposite sense of rotation in subsequent passage pipes in subsequent basic carriers.
Such liquid separators as illustrated in DE 10 2004 037 157 A1 already show a good liquid separation function.